An air treatment method for removing a contaminant is provided, comprising: providing air containing the contaminant for treatment; providing a plurality of multi-staged non film forming polymer particles having a core polymer and at least one shell polymer; and contacting the multi-staged non film forming polymer particles and the for treatment air; wherein the core polymer accounts for 1 to 25 wt% of the weight of the non film forming polymer particles provided; the multi staged non film forming polymer particles provided each contain a central void; and the contaminant is extracted from theair for treatment, producing treated air depleted in the contaminant.